1. Field of the Invention
The present invention relates to a heat dissipating device for lightings; in particular, a heat dissipating device that directs the airflow to increase heat dissipation.
2. Description of Related Art
A light emitting diode (LED) has several advantages such as being eco-friendly, high brightness, energy saving, and long service life. Therefore, it has been widely used in various lighting applications. However, it produces high temperature during light emitting. If the heat cannot be dissipated properly, the illumination performance would be adversely affected and even burn out the lightings.
Referring to FIG. 1 and FIG. 2, which illustrate a conventional heat dissipating devices of type MR16 and E27 respectively. Both devices include a light source module 7, a heat sink 8, and a converter 9. The light source module 7 includes at least one light source 71, a circuit board 72, and a lens 73. The light source 71 is a light emitting diode (LED) and is located on the circuit board 72. The lens 73 is mounted under the light source 71. When the light source 71 is turned on, light is emitted through the lens 73.
The heat sink 8 is connected to the light source module 7. The heat sink 8 has a substrate 81 and a plurality of heat dissipating fins 82 extending outward from the outer edge of the substrate 81. A plurality of channels 83 is formed between the heat dissipating fins 82 for air to flow through to take away heat from the heat sink 8. A connector 84 is connected to the middle or bottom of the substrate 81. The light source 71 and the circuit board 72 of the light source module 7 are located on the connector 84, so that the heat generated from the light source module 7 can be transferred to the heat sink 8.
The converter 9 is connected to the top of the heat sink 8. As shown in FIG. 1, the converter 9 of the MR16 lighting has an insulating socket 91 and two pins 92. The two pins 92 are electrically connected to the light source 71 and the circuit board 72 of the light source module 7, so as to transmit the power to the light source 71 and the circuit board 72.
Referring to FIG. 2, the converter 9 of the E27 lighting has an insulating socket 93 and an electrically conductive terminal 94. The conductive terminal 94 is electrically connected to the light source 71 and the circuit board 72 of the light source module 7, so as to transmit the power to the light source 71 and the circuit board 72.
However, the channels 83 of the conventional heat sink 8 can only direct the airflow between the heat dissipating fins 82 along the outer edge of the heat sink 8. The airflow cannot enter the centre of the heat sink 8. The resulting heat dissipating effect is significantly weakened.
Therefore, there is a need of a novel structure which overcomes the above disadvantages.